The emergence of low Earth orbit (LEO) satellite mega-constellations is dynamically transforming the space sector. While free-space optical (FSO) links efficiently facilitate intersatellite data forwarding, they suffer from atmospheric/weather conditions in the space-to-ground link. This study delves into utilizing high-altitude platform stations (HAPS) as elevated relay stations strategically positioned above terrestrial ground stations. We introduce the concept of high-altitude ground stations (HAGS), an innovative approach to enabling the development of all optical LEO satellite constellations. The first contribution is an analysis of the HAGS-based network architecture where the LEO spacecraft only hosts FSO transceivers. Secondly, we execute an extensive simulation campaign to determine the gain of HAGS, including a new equivalency model with the traditional ground station approach. Finally, we examine the research challenges of implementing HAGS-based, all optical LEO mega-constellations.

翻译：低地球轨道(LEO)卫星巨型星座的兴起正在深刻改变航天领域。虽然自由空间光(FSO)链路能高效实现星间数据转发，但在星地链路中易受大气/天气条件影响。本研究探索将高空平台站(HAPS)作为战略性升空中继站，部署于地面站上方。我们提出高空地面站(HAGS)概念——这一创新方案旨在实现全光LEO卫星星座的构建。首先，我们分析了基于HAGS的网络架构，其中LEO航天器仅搭载FSO收发器。其次，通过大规模仿真实验确定HAGS的增益，并建立与传统地面站方法的新型等效模型。最后，我们探讨了实现基于HAGS的全光LEO巨型星座所面临的研究挑战。